The present invention relates to computer software utility programs, and more specifically to programs in the field of computer-aided design (CAD), computer aided manufacturing (CAM), and computer aided engineering (CAE). More generally, it relates to the display of multiple views of an object as seen from different positions with respect to the object.
In CAD/CAM/CAE systems, parts or objects can be designed using three dimensional modeling software. An object designed using such software is composed of a number of faces, each of which has a set of edges. The information related to the decomposition of a three dimensional (xe2x80x9c3Dxe2x80x9d) solid into faces, edges and vertices, and the logical relationships between these elements, is known as topological information, and is stored in topological journals.
In the field of CAD/CAM/CAE various tools are available to a designer for the purpose of facilitating the design and analysis of an object or part. Once the object has been finally designed, a drawing is created to be sent to a machinist or supplier for the purpose of giving the machinist or supplier the information that is necessary to make the object. A drawing can contain various two dimensional projections of a part, such as for example, a top view, a left-side view, a right-side view, a bottom view, etc., and normally contains several different projected, cutting or detailed views of an object. These drawings are created so as to comply with various industry standards, such as ISO, JIS, and ANSI, for example, so that all the necessary information is provided to the machinist for making the part. Typically, the drawing is supplied in electronic format.
To simplify the job of a drafter, tools exist that automatically create a final two dimensional drawing for an object, in the proper format and convention so as to be understood by the machinist or supplier, from the three-dimensional model. The result is a drawing having xe2x80x9cgenerativexe2x80x9d views, which inherit some topological information contained in the initial 3D solid model. Additionally, a 3D representation of the object, which corresponds to the outer shell of the body, is usually extracted from the 3D solid model, and has an associated subset of topological information. This 3D representation is usually displayed in a 3D viewer. It makes drawing and 3D representations independent from the 3D solid model.
However, in a drawing, the geometry represented is a wireframe representation of the 3D solid projected into a drawing view, and has no semantic (such as face or edge); it is a collection of line segments. The relationships between line segments in a drawing and edges or faces in a 3D solid are established through tables associating each line segment in a view to an edge. Face identification is then performed from edges through the topological journals. In this document, when reference is made to edges or faces in a drawing view, it should be understood that what is referred to is line segments representing these edges or faces.
When an object has a complex geometry it can be difficult to keep track of the various faces and features of an object when displayed in various views of the drawing. This can lead to uncertainty and confusion. The more complex an object, the more severe the problem. For example, a supplier may receive a drawing with twenty or more views of the object. It can be extremely difficult for a person to understand and track an aspect of the geometry of an object in different views.
Therefore, there is a need to provide the user with visual clues that identify common portions of an object when displayed in different views in a drawing. This would aid the user to visualize the object and its features more clearly and definitely.
Accordingly, the present invention provides a system, method, and apparatus for providing a visual tool showing correspondence between views of the same portion of an object in every view of a drawing.
According to the invention, a user may select a specific portion or feature of an object. When such selection is made, the portion or feature of the object is automatically highlighted in each of the other views being displayed. In the preferred embodiment, this portion or feature is also highlighted in a window where the object is represented in three dimensions.